1. Field of the Invention
The present invention relates to an ink jet recording apparatus and a recovery method, and more particularly to an ink jet recording apparatus having an ink jet recording head of the cartridge type detachable from a main body and a recovery method at the exchange of cartridge.
2. Related Background Art
Recording apparatuses having the features of printer, copying machine, facsimile apparatus or the like, or recording apparatuses for use as the output device from a complex electronic equipment or work station including a computer or word processor are constituted to record the image (including characters) onto a recording sheet (recording medium) such as a paper or plastic thin plate, based on the image information (including character information). Depending on the recording method, such recording apparatuses can be classified into the ink jet system, wire dot system, thermal system and laser beam system.
In a recording apparatus of the serial type based on the serial scan method of scanning in a direction transverse to a conveying direction (sub-scan direction) of recording medium, the overall recording is carried out on the recording medium by repeating the operation of recording (or main scanning) the image with recording means mounted on a carriage movable along the recording medium, after setting the recording medium at a predetermined recording position, feeding sheet (or conveying the recording medium) by a predetermined amount after terminating the recording of one line, and then again recording (or main scanning) the image at the next line on the recording medium which is stopped. On the other hand, in a recording apparatus of the line type in which the recording is conducted only by sub-scanning in a conveying direction of recording medium, the overall recording is performed on the recording medium by repeating the operation of setting the recording medium at a predetermined recording position, consecutively recording one line collectively and then feeding sheet (pitch feeding).
Among the above recording apparatuses, a recording apparatus of the ink jet system (an ink jet recording apparatus) is configured to perform the recording on the recording medium by discharging the ink from recording means (recording head) in accordance with an image signal, having the advantages in which recording means can be made compact, high definition image can be recorded at a high speed, the ordinary paper is usable for recording without needs of any special treatment, the running cost is low, there is less noise owing to the non-impact method, and the color image is easily recorded by using color inks. In particular, a line-type recording apparatus using recording means of the full-multi type in which a number of discharge orifices are arranged in a direction of sheet width allows for higher speed recording.
Specifically, recording means (recording head) of the ink jet system of discharging the ink by the use of heat energy can be easily fabricated with an arrangement of liquid channels (discharge orifices) at high density by forming electricity-heat converters, electrodes, liquid channel walls, and a ceiling plate as the film on a substrate through a semiconductor fabrication process such as etching, vapor deposition or sputtering, thereby allowing the recording of high definition image at higher speed in a simple and compact construction. On the other hand, there are a variety of requirements for the material of recording medium, and in recent years, besides a paper or resin thin plate (e.g., OHP) which is an ordinary recording medium, the use of a thin paper or processed paper (punched paper for filing, scored paper, or any shaped paper) has been demanded.
By the way, such an ink jet recording apparatus involves two types in which the ink recording head is exchanged simply by the user and by the service-man at the user's site. The former is usually a cartridge type ink recording head, and the latter is an installed type ink recording head.
In particular, the former ink jet recording apparatus using a cartridge type recording head is noted because it is small and free of maintenance. Such recording head of the cartridge type may contain storage means for storing the control information specific to the head or drive control means for the head.
The ink recording head of the cartridge type exchangeable from the recording apparatus typically comprises a plurality of heat generating elements for the discharge of ink which are arranged simply or as a matrix, wherein the main device powers these heat generating elements at a predetermined drive timing to discharge the ink. However, a recent ink jet recording apparatus for the output of color image has a trend of improving the recording quality by comprising, on the recording head side, but not the main device side, storage means for storing control information for the correction for density unevenness inherent to the recording head, drive pulse information, resist information for the adjustment of recording position, which were not required in the conventional monochrome recording apparatus. In order to transfer a variety of information from the recording apparatus to the main device control unit, a power for the control of the main device (hereinafter denoted as V.sub.CC) must be also supplied to the recording head.
However, in an apparatus in which the user can simply detach the recording head of the cartridge type, there is a risk that the stored information within the recording head may be destroyed due to reduced reliability of electrical contacts between main device and recording head, the dispersion in positional accuracy, and the contact order between contact points.
If such information is destroyed, the cartridge may become unusable, and in the worst cases, the apparatus itself may be damaged.
On the other hand, in the ink jet recording apparatus, when the ink may not be discharged through certain discharge orifices for a long time depending on recording data, or when the apparatus itself is not used for a long time, the ink within discharge orifices or liquid channels communicating to discharge orifices may be thickened due to evaporation of water content. If the liquid channels are placed in such an unsuitable state for the discharge owing to accumulation of such thickened ink, there is a risk that the discharge quantity of ink may be unstable even if the discharge energy generating elements arranged in liquid channels are driven under certain predefined conditions, resulting in degraded quality of recorded image. Also, a discharge failure may arise due to such thicker ink, or moreover the undischarge may arise due to stiffness of the ink.
Also, in the ink jet recording apparatus, if ink droplets, water droplets, or dirts adhere to the recording head face (discharge orifice formation face) on which ink discharge orifices are provided, there is also a risk that the discharged ink may be pulled off by these adherents, deviating the discharge direction, and reducing the image quality.
To resolve these inconveniences caused by the use of the liquid ink as the recording agent, the ink jet recording apparatus is provided with a specific constitution as not found in other recording apparatuses, that is, a so-called discharge recovery system for the recording head, including means for refreshing the inside of liquid channel and means for rendering the discharge orifice formation face excellent.
For the discharge recovery system, there are various constitutions, wherein means for refreshing the inside of liquid channel is discharging the ink onto a predetermined ink receiving medium by driving discharge energy generating elements (also referred to as preliminary discharge or idle discharge). Also, there is means for compulsorily discharging the ink through discharge orifices by pressurizing the ink supply system or sucking the ink through discharge orifices.
Also, means for preventing the deflection in the discharge direction by refreshing the discharge orifice formation face is cleaning off (wiping) ink droplets and dirts adhering to the periphery of discharge orifices by providing a wiping member which comes into contact with the discharge orifice formation face and behaves in relative movement thereto.
By the way, the head cartridge is packaged and distributed, apart from the recording apparatus main device, and may be stored over a long term. In such a case, when a package is opened and a cartridge is mounted on the main device, it is requisite to securely perform the recording without degradation in image quality.
Thus, when the head cartridge is stored for a very long term, the discharge orifice portion may be closed due to thicker or fixed ink. Also, when the cartridge is removed temporarily and left away for a long time, the discharge orifice portion may be closed.
Even if such a head cartridge is processed through the recovery operation which is normally performed during the recording, all the nozzles may not be completely recovered.
In addition, an ink jet recording apparatus for recording using the cartridge often adopts a constitution of using a common drive source for drive members to accomplish the compactness. In any case, where the drive source for recovery means and that for other drive member are commonly used, if the normal recovery operation is not performed, recording quality may be degraded and the reliability of recording apparatus may be decreased.